Ennever J F, Knox I, Denne S C, Speck W T
Pediatr Res. 1985 Feb;19(2):205-8. doi: 10.1203/00006450-198502000-00012.
Phototherapy results in the conversion of native bilirubin to more water-soluble configurational and structural isomers. The serum half-life for the configurational isomer, the principal photoproduct in vivo, was determined by high pressure liquid chromatography in six premature infants following cessation of phototherapy. The mean half-life for this isomer was 15 h. The excretion of this isomer, calculated from the measured half-life, is less than half of daily bilirubin production, and therefore cannot account for the total bilirubin elimination observed during phototherapy. The serum concentration of the structural isomer, lumirubin, is lower than that of the configurational isomer; however, excretion is more rapid (serum half-life less than 2 h). Because of its rapid excretion, lumirubin may be an important pathway for bilirubin elimination during phototherapy.
光疗可使天然胆红素转化为水溶性更高的构型异构体和结构异构体。通过高压液相色谱法测定了6例早产儿停止光疗后体内主要光产物——构型异构体的血清半衰期。该异构体的平均半衰期为15小时。根据测得的半衰期计算，该异构体的排泄量不到每日胆红素生成量的一半，因此无法解释光疗期间观察到的总胆红素消除情况。结构异构体鲁米诺胆红素的血清浓度低于构型异构体；然而，其排泄更快（血清半衰期小于2小时）。由于其排泄迅速，鲁米诺胆红素可能是光疗期间胆红素消除的重要途径。
